Recently, display devices trend toward light weight and low power consumption. In particular, flat panel display devices such as an LCD (liquid crystal display), a PDP (plasma display panel) and an OELD (organic electroluminescence display) are being distributed.
A flat panel display device includes a data receiving device which provides a signal for representing an image, to a display panel. The data receiving device is configured to use a differential signal transmission scheme, such as a mini-LVDS (low voltage differential signaling) scheme and an RSDS (reduced swing differential signaling) scheme, capable of transmitting data at a high speed while reducing electromagnetic interference (EMI), as an interface technology for signal transmission. It is the norm that the differential signal transmission scheme is realized in such a way as to separately receive a clock signal to be used in data recovery and a data signal for representing an image.
However, in the case of the differential signal transmission scheme in which a clock signal and a data signal are separately transmitted, an impedance mismatch may occur in a line for transmitting the clock signal. If reflective waves are generated in the line for transmitting the clock signal due to the impedance mismatch, the data receiving device may be encountered with a problem in that signal distortion and electromagnetic interference increase by the reflective waves.
In order to cope with this problem, a data receiving device may use an interface technology using a signal in which a clock signal is embedded in a data signal. The signal in which a clock signal is embedded in a data signal may be defined as a clock-embedded data signal. In the clock-embedded data signal, dummy data and a clock signal are embedded together between data signals.
In the case of using the clock-embedded data signal, the recovery of a clock signal may be implemented by detecting the state of the clock edge of an embedded clock signal after dummy data.
A conventional data receiving device uses a clock-embedded data signal in which the clock edge of an embedded clock signal is fixed to a rising edge or a falling edge. Therefore, in a device for interfacing a transmission side and a reception side to receive data, it is difficult to prevent electromagnetic interference from increasing at a specified frequency.
Hence, the suggestion of a protocol of a clock-embedded data signal invulnerable to electromagnetic interference and the suggestion of a clock recovery technology capable of recovering a clock signal in correspondence to the changed protocol are demanded in the art.